Luminaire



Aug. 26, 1941.

H. J. FLAHE'RTY LUMINAIRE Filed Dec.

Inventor' Harold J. Flahel -tm r-hs Attorney.

Patented Aug. 26, 1941 LUMINAIRE em J. Flahcrty, s General Electric Compaugus, Mass, assignor to any, a corporation of ApplicatioriDeccmber 15,1939, Serial No. 309,438

My invention relates to luminaires, and-more particularly to outdoorluminairesy Luminaires exposed .to weather conditions and used forstreet lighting and highway lighting purposes are generally suspendedfrom a tubular supporting structure through which the conductors for thelight source are brought into the luminaire. For the purpose of keepingout water, dust, and insects, the luminaire is enclosed as far aspossible. It is impossible, however, to close the luminaire against thetubular support through which the conducting cable enters the luminaireand considerable trouble is here encountered because of water enteringthe luminaire at this point.

Tubular supports are, almost without exception, made of metal upon whichwater vapors condense. The vapor gets into the support through openingswhich develop during the life of the supports and against which there isno practical safeguard. The change of temperature within the luminairebetween periods of operation sets up a circulation of air out of whichmoisture condenses on the inner surfaces of the tubular support andgathers in droplets which tend to move toward the luminaire. If a dropof this moisture falls on the lamp, or upon the globe, during operationof the luminaire, the lamp glass, or globe, cracks and is destroyed.

The primary object of my invention is to provide an improvedconstruction of luminaire to prevent water entering the luminairethrough its tubular support without interfering with the desiredinterior cables or wiring thereof.

For a better understanding of my invention, together with other andfurther objects thereof, reference is had to the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

In the accompanying drawing, Fig, 1 illustrates a conventional street orhighway luminaire with its tubular support, and Fig. 2 is an enlargedcross sectional view of a portion of the luminaire of Fig. 1illustrating my invention.

Referring to Fig. 1 in detail, the luminaire comprises a globe ID, areflector housing II, and a cap l2. The cap I2 is attached to a pipefitting |3 which joins the luminaire to a horizontal tubular bracket M.The tubular bracket is joined to a suitable column |5 by anotherdecorative pipe fitting |6. A scroll l'| braces the bracket against thecolumn, being attached to these members respectively by clamps l8 andI9.

Referring to Fig. 2, the cap I2 is illustrated in tubular portion 24.

a cross-sectional view taken through the center thereof. The cap iscylindrical, having a reduced diameter throat portion 20, into the endof which the fitting I3 is threaded. At the joint of the throat portion20 and the slightly tapered body portion 2| cf the cap, a conicallyshaped member 22 is provided through which the cable for the lightsource is brought into the cap. The conical member is slightly greaterin diameter at its lower end, than the inside of the body 2|, so thatwhen the conical member 22 is assembled with the body 2|, its lower endwhich is provided with a flange 23 is pressed into position against thewall of 2| and is held, partly by friction, at the line of intersectionof the portions 20 and 2| of the cap l2.

The upper end of the conical member 22 is provided with a tubularportion 24, the outside diameter of which is made smaller than theinside diameter of the fitting l3, and is made concentric with it. Thisdifference in diameters between the inside of the pipe fitting I3 andthe outside of the tubular portion 24 is made small because it isdesired to keep the inside diameter of the tubular portion as nearly aspossible the same as the inner diameter of the fitting l3 and therebyminimize the interference with the passage of cable from the fittingthrough the portion 24 to the cap. The diiference is made large enoughonly to enable the water flowing along the inner surface of the fittingl3 to drop vertically to the outer surface of the conical member 22 tobe thereby directed into an annular space formed between the surface ofthe conical member 22 and the section 20 of the cap l2. An opening 25 isprovided in the wall of the member 2|], permitting this water to escape.A suitable cement and rivets 26 are used toinsure a perma nentwater-tight joint between the flange 23 and the cylinder 2|.

The conical member 22 is provided witha lug 21 projecting downwardlyinto the cap. A bracket 28 and screw 29 support a socket 30 for anincandescent lamp 3| in line with the axis of the The lamp 3| projectsinto the reflector H and constitutes the light source.

This simple arrangement within the luminaire is efficient for the reasonthat the moisture within the tubular support, or pipe fitting, |3condenses on the metal surface of the support and not upon the cablewhich is nearly always at a higher temperature than the support andcools at a slower rate than the support when the 1umi-' naire ceasesoperation. The condensed moisture drops vertically since there are noair currents to alter its course. Hence the difference between theoutside diameter of the tubular portion 24 and the inside diameter ofthe tubular support need be small; resulting in a minimum ofinterference with the passage of the cable through the conical member 22into the luminaire.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a street lighting luminaire including a globe, a reflector housingand a cap joined to each other to form a water-tight enclosure for alight source, the combination of a lamp socket mounted in said cap, ahollow pipe support joined to said cap, and arranged to guide conductorsto said socket, a conical member mounted in said 15 cap between saidpipe support and said socket, said conical member havingan upper openingconcentric with the said pipe support and an outside diameter smallerthan the diameter of the opening in said pipe support, said memberhaving its lower end in water-tight relationship with said cap, wherebywater dripping into said cap from said support falls on the outersurface of said conical member and is thereby diverted into the chamberdefined by the conical member and the wall of said cap.

2. In a street lighting luminaire including a globe, a reflector housingand a cap joined to each other to form a water-tight enclosure for alight source, the combination of a lamp socket mounted in said cap,ahollow tubular support joined to said cap and, arranged to guideconductors to said socket, a conical member mounted in said cap betweensaid tubular support and said socket, said member being provided with anupper opening concentric with the said tubular support and an outsidediameter smaller than the opening in said tubular support, said memberhaving its-lower end in water-tight relationship with said cap and saidcap having an opening through its wall at the edge of said memberwhereby water dripping into said cap from said support falls on theouter surface of said conical member and is; thereby diverted anddrained from said cap.

HAROLD'Jr FLAHERTY.

